It is known that, in laser fusion, a nuclear fusion burning rate that is an important indicator of its nuclear fusion phenomenon is heavily dependent on a fuel areal density ρR (plasma density×plasma radius, g/cm2) in an implosion plasma. Therefore, the emphasis is on measurement and evaluation of a fuel areal density ρR in monitoring and controlling of a nuclear fusion phenomenon (for example, refer to Non Patent Document 1).
One of the most important development subjects is to achieve a high fuel areal density in the realization of laser nuclear fusion. For example, a fuel areal density of approximately ρR>3 g/cm2 is required in an implosion plasma in which ignition-and-burn is assumed.